7/22/2009 @ 1:45PM

Overrating Chemical Risk

Now that global warming has been addressed by Congress, some politicians are gearing up to take on a no-less fearsome local menace. “We already have tough regulations for pesticides and pharmaceuticals,” explained Sen. Frank Lautenberg, D-N.J., to the Environmental Working Group, an activist organization that wants chemical regulation in the U.S. radically overhauled, “it’s common sense that we also have tough regulations for chemicals that end up in our homes.”

This goal sounds eminently sensible. There have been hundreds of stories and studies warning us that virtually every affliction imaginable, from cancer to obesity, can be linked to tiny amounts of chemicals in our blood–chemicals we appear to absorb, with ne’er a care from industry, from using such mundane items as frying pans, air fresheners, iPod earbuds and lipstick.

Why are we even taking these kinds of risks when we could follow Canada and Europe and adopt the precautionary principle, forcing industry to prove that the chemicals they use are safe before they reach the public? This is the aim of Sen. Lautenberg’s Kids-Safe Chemical Act, which he hopes to reintroduce in Congress sometime in the next year. And who could possibly disagree with this bold attempt to protect children from chemicals, except, of course, the chemical industry?

But common sense does not always reflect sensible science or lead to rational science policy. And there is one rather important constituency that doesn’t see the warnings by activists or their legislative recommendations as the triumph of scientific thinking–namely, the scientists who study the risks of chemicals. This is one of the surprising conclusions that emerge from taking conventional wisdom as it has bubbled up in public debate and pricking it with a survey of expert opinion.

In response to growing hysteria over toxic chemicals, we decided to survey members of the Society of Toxicology, the field’s professional organization, on a range of issues. Nine hundred and thirty-seven scientists responded in full through an online questionnaire administered by Harris International. Whether based in academia, government or industry, we found that significant majorities challenged the supposedly “common sense” of chemical risk.

Fewer than one in four, for example, believed chemical regulation should be guided by the precautionary principle or that chemical regulation in the U.S. is inferior to that in Europe. Eighty-one percent disagreed with the idea that any level of a chemical in the blood shows a health risk and 92% disagreed with the idea that any exposure level is unacceptable. Furthermore, many of the chemicals that have been making news in the past few years were not seen as posing a high risk (for example, just 3% said Teflon posed a high risk), while the activist groups that have agitated for bans on these chemicals, such as the Environmental Working Group, were seen by a majority of scientists (almost 80%) as overstating risk.

How did this radical disconnect between those who talk about science in public policy and those who actually do the science come about? Our survey suggests that Toxicologists blame the media: 97% said journalists did a poor job in distinguishing good studies from bad studies along with such key concepts as correlation from causation (one cannot assume that just because a disease and a chemical are both present, the former is caused by the latter). Roughly three out of four scientists thought the media gave too much attention to studies by environmental activist groups and failed to place new studies in the context of the overall body of evidence.

To illustrate this in real terms, the Environmental Working Group claims that “millions of babies” are at risk from the chemical bisphenol A (BPA) in beverage and food containers, based on “low-dose” scientific evidence. Europe, meanwhile, even though it follows the precautionary principle, found that “low-dose” evidence unreliable and sees no reason for a ban. In fact, the Swiss Federal Office of Public Health explained that a ban would be more risky to the public because it would be lead to swapping a chemical that was safe with one that was new and relatively untested.

And this was not simply a theoretical concern. BPA is used to protect against food contamination from bacteria, such as the botulinum, which is only exceeded by Ricin in the chemical league table for lethality. Botulinum, which attacks the nerves, can kill an adult in a dose as low as one-hundred-millionth of a gram.

Ironically, and as an illustration of the fundamental toxicological principle that the dose makes the poison, tiny amounts of botulinum are also used to treat severe conditions such as cerebral palsy and, as Botox, less severe ones like wrinkles.

Tough talking chemical regulation, in other words, if backed only by flimsy research and the simplistic notion that if there are chemicals in the blood, there’s a risk, could have all manner of unintended and deleterious consequences to public health. Common sense suggests two courses of action: listen to the scientific consensus and think about the risks of banning something before you ban it.

Trevor Butterworth is editor of STATS.org, an affiliate of George Mason University.